Managing Serviceguard 14th Edition, June 2007

Planning and Documenting an HA Cluster
Package Configuration Planning
Chapter 4170
When adding packages, be sure not to exceed the value of
max_configured_packages as defined in the cluster configuration file.
(see “Cluster Configuration Parameters” on page 154). You can modify
this parameter while the cluster is running if you need to.
Choosing Switching and Failover Behavior
Failover packages (see “Package Types” on page 71) can be configured so
that IP addresses switch from a failed LAN card to a standby LAN card
on the same physical subnet. To enable this behavior, use the
local_lan_failover_allowed parameter. (yes, meaning enabled, is the
default.)
To determine the failover behavior of a failover package, you define the
policy that governs where Serviceguard will automatically start up a
package that is not running. In addition, you can define a failback policy
that determines whether a package will be automatically returned to its
primary node when that is possible.
Table 3-3 on page 82 describes different types of failover behavior and
how to set the parameters that determine each behavior.
Parameters for Configuring EMS Resources
NOTE The default form for parameter names and literal values in the modular
package configuration file is lower case; for legacy packages the default
is upper case. There are no compatibility issues; Serviceguard is
case-insensitive as far as the parameters are concerned. This manual
uses lower case, unless the parameter in question is used only in legacy
packages, or the context refers exclusively to such a package.
Serviceguard provides a set of parameters for configuring EMS (Event
Monitoring Service) resources. These are resource_name,
resource_polling_interval, resource_start, and
resource_up_value. Configure each of these parameters in the package
configuration file for each resource the package will be dependent on.
The resource_start parameter determines when Serviceguard starts
up resource monitoring for EMS resources. resource_start can be set
to either automatic or deferred.